Fully Distributed State Estimation for Power System with Information Propagation Algorithm

Abstract

In this paper, a new fully distributed state estimation (DSE) based on weighted least square (WLS) method and graph theory is proposed for power system. The proposed method is fully distributed so that the centralized facilities, e.g., supervisory control and data acquisition (SCADA) and centralized estimators, are not required. Also, different from the existing DSE methods, the proposed method is a bus-level DSE method, in which the power system is not required to be partitioned into several areas. In order to realize the proposed fully distributed DSE method, a novel information propagation algorithm is developed in this paper. This algorithm has great potential in future applications since it is useful to broadcast the local information of the nodes to the entire system in a fully distributed network. The proposed DSE method is compared with the conventional centralized state estimation method and existing multi-area DSE method in different models in this paper. The results show that the proposed method has better performance than the traditional methods.

Fully Distributed DC Optimal Power Flow Based on Distributed Economic Dispatch and Distributed State Estimation

“…The distributed state estimation is a method to estimate the states of power systems without centralized facility. In order to realize the distributed state estimation, an information propagation algorithm is proposed in paper [10] as follows,…”

“…According to the information propagation algorithm (6), the distributed state estimation algorithm is developed in [10] as shown in the equations (7),…”

“…The first equation (7b) in the algorithm describes the input of the algorithm, where 7c) is the information propagation algorithm with weight coefficient w Z ij . In addition, the equation (7d) represents the distributed estimation with least square method [10,14]. The initial values of the algorithm are: Z i,i (0) = z i,i (0); Z i,j (0) can be arbitrary number (e.g.…”

“…where P g and P L are the power injection vector of the generator buses and load buses, respectively. T g is a matrix constructed according to (10) but with only the generator buses. Similarly, T L is developed by considering only the load buses.…”

“…The reason is that the power flow analysis is hard to be decomposed since the calculation of power flow requires the information across the entire power system (or at least a part of the system). In order to achieve the completely distributed OPF, a new OPF method is developed in this paper based on the distributed economic dispatch (DED) method [9] and the distributed state estimation (DSE) method [10]. In this scheme, the proposed method includes two algorithms.…”